Disconnect switch for high voltage lines



June 4, 1957 H. THOMMEN E'IAL 2,794,870

DISCONNECT .SWITCH FOR HIGH VOLTAGE LINES Filed July 11, 1955 2Sheets-Sheet 1 IN VENT ORS ATTORNEYS June 4, 1957 THQMMEN. r 2,794,870

DISCONNECT SWITCH FOR HIGH VOLTAGE LINES Filed July 11, 1955 2Sheets-Sheet 2 15 Li a INVENTOR'S 1 JW& J /Jaw ATTORNEYS Unite StatesPatent t'fice 2,794,870 Fatented June 4, 1957 DISCONNECT SWITQH FOR HIGHVOLTAGE LINES Hans Thommen, Baden, and Lothar Butz, Nussbaumen,

near Baden, Switzerland, assignors to A ktiengesellschaft Brown, Boveri& Cie, Baden, Swrtaerland, a joint stock company Application July 11,1955, Serial No. 521,284

Claims priority, application Switzerland July 13, 1954 13 Claims. (Cl.200-48) become known to date have the disadvantage that a reliableclosing of the switch contacts cannot be insured under all conditions,namely as a result of a change of position of the fixed countercontactduring operation. This is the case especially with overhead lines where,through wind pressure, temperature variations, ice formation, etc.considerable changes of position of the line carrying the countercontactmay occur. To eliminate this disadvantage, a variety of contactarrangements have been proposed, but they are complicated andaccordingly high in cost, and moreover, difiiculties arise in connectionwith their operation. Also, a reliable interception of the fixed,countercontact can be achieved only by a design of the movable contactsuch that the spatialextent of the latter during the closing movementbecomes inadmissably big.

The invention relates to a high voltage disconnector of the column typefor which a reliable closing of the switch is made possible in a verysimple manner. According to the invention, this is achieved in that themovable contact is suspended from the high voltage line while the fixed,countercontact is located on the lower supporting insulator of thedisconnector, so that the contact connection occurs through a movementfrom the top down.

The invention will be further explained with reference to the drawing,diiferent examples of a disconnector according to the invention beingshown diagrammatically in Figures 1 to 4.

In all embodiments the movable i. e. lowerable contact is suspended froma line 1 of an upper collector bar or overhead system, while the fixedcountercontact is located on the supporting insulator 2 of thedisconnector.

In Fig. 1 there is illustrated an embodiment for the disconnector, ordisconnect switch as it is also called, wherein the movable, lowerablecontact is constituted by an electrically conductive weight 3 which issuspended from the line cable 1 by means of a flexible, electricallyconductive cable which is arranged to be wound and unwound on a drum 4carried by a support 9. The drum 4 is driven in the desired direction toraise or lower the weight 3 by means of transmission gearing driven bysuitable means and having gears indicated by numeral 6. The upper end ofthe cable 5 is electrically connected to the line cable by suitablemeans, not shown, andthe weight 3 is adapted to engage the fixed,countercontact member 3a on the supporting insulator 2 as it is loweredby unwinding the cable 5 from drum 4. As previously indicated, the line1 is subject to swinging motions attributable to various causes with theresult that it becomes desirable to assure engagement between thecontact members 3, 3a notwithstanding any swinging, pendulum like motionof the weight contact 3 due to motions of the line which are transmittedto the weight contact 3 through the flexible cable 5. To this end itwill be observed that complementary configured, coengageablefrusto-conical male and female frame elements 7, 8 are associatedrespectively wit-h the weight contact 3 and the fixed contact 3a suchthat the weight contact 3 will always be guided into direction positionover the fixed contact member 3a as the former is lowered into proximitywith the latter. In Fig. 1 the disconnect switch is shown with thecontact members 3, 3a in engaged position thus establishing anelectrical connection from line 1 through cable 5 and contact members 3,3a to a branch line such as the line 1a that can be supported at the topof the insulator column 2. Fig. 1a shows the contact members 3, 3a inseparated position in which the cable 5 is substantially completelywound upon the drum 4.

In the embodiment illustrated in Fig. 2, the lower, fixed contact beingomitted for purposes of simplification since it is identical with thearrangement shown in Fig. 1, it will be observed that the cable 5 whichis wound and unwound on drum 4' has one end S'a secured to thesupporting frame 9 and the other end secured to the drum 4. The weightcontact 3' has an eyelet 10 secured to the same and the cable 5' passesthrough the eyelet. Thus as the cable 5' is wound and unwound on thedrum 4 the weight contact 3' will be raised and lowered, respectively.Otherwise, the structure is identical with that shown in Fig. 1.

Figs. 3 and 3a illustrate an embodiment wherein the movable, lowerablecontact member is suspended from the line cable 1 by means of a togglelever arrangement. The movable contact member 11, preferably designedwith one or more spade-like contact parts, is adapted, upon lowering toengage a trough-shaped, fixed, countercontact 19 carried at the upperend of the pedestal insulator 2. The spade-like configuration for themovable contact member 11 cooperates with the complementary configuredtrough-like fixed contact 19 in the same manner as the frusto-conicalmembers 7, 8 in the embodiment of Fig. 1, namely to assure engagementbetween the contact members notwithstanding swinging movement of themovable contact member 11 due to movement of the line 1. Fig. 3 showsthe movable contact member 11 in the lowered position in engagement withthe fixed, countercontact member 19, and Fig. 3a shows the contactmember 11 in the raised position. The movable contact 11 is located atthe free end of the lower arm 12 of the toggle, while the other leverarm 13 of the toggle, constructed in the form of a tube, is rotatablydisposed at the line cable 1. At one end of lever arm 13 revolving abouta fixed axis at the line cable 1 there is a sprocket wheel 14 concentricwith the axis of rotation, and a second sprocket 15 is located at theopposite end of lever arm 13 concentric with the axis of rotation oflever arm 12 so that a differential movement is produced between the twolever arms. The sprockets 14 and 15 are interconnected by a sprocketchain 16. Actuation of the toggle comprised by levers 12, 13 is effectedby means of another lever 17 which is articulated to the toggle lever 13and is caused to rotate by a suitable driving mechanism. In the closedposition, where the movable contact member 11 is engaged with the fixedcontact member 19, the toggle levers 12, 13 are disposed inoutstretched, aligned position as is clear from Fig. 3, while in switch,the toggle levers 12, 13 are folded.

Various types of drive mechanisms may be utilized for actuating thetoggle levers 12, 13. The drive 30, e. g. compressed air or an electricmotor, is mounted atop a gantry 31 to which one end of the cable 1 isanchored by means of laterally extending'arm 33 of insulating material.The movements of the drive are transmitted from the drive itself throughan insulating shaft 32 and an endless rope 18 to the lever mechanism 17for actuating the toggle levers 12, 13. It is possible also to make theentire transmission from the drive to the disconnect switch mechanismonly by means of a rope or an insulated shaft. Naturally the drive mayalso be disposed at a different point on the gantry, for example atmid-height, or even on the ground at the foot of the gantry. Then also,the drive may be mounted on a special supportinginsulator and thecontrol movements may be transmitted to the movable contact member ofthe disconnecting switch by means of a rope. For manual operation of themovable contact member in the event of an emergency, a supplementarycompressed air tank can be provided, the tank being disposed parallel tothe supply line for the compressed air drive. The drive as describedabove for the embodiment of Figs. 3 and Sa'can also be applied to theembodiment shown in Figs. 1 and 1a.

Still another embodiment of the invention is illustrated in Figs. 4 and4a. Here the movable contact member 20 in the form of a downwardlyopening U-shaped member with spreading arms 20a is mounted at one end ofa tubular bar 21 which is mounted for rotation approximately in thecenter at the line cable 1. Bar 21 which, in the disconnected position(Fig. 4a) is parallel to the line cable 1, is first caused to rotatethrough an angle of about 90 by means of a transmission gearing during aconnection stroke and then is caused to move downward until the arms 20aof the contact member 20 embrace the fixed contact 22. Details of themovement of bar 21 are as follows: First the bar 21 is rotated throughan angleof about 90 by means of a toothed segment 23 which comes intoengagement with a gear wheel 24 disposed on bar 21. By such movementanother gear wheel 25, on whose axis a roll of wire rope 27 is rigidlycottered, is likewise rotated through an angle of about 90 and comesinto engagement with a spatially fixed gear wheel 26, owing to which thebar 21 is let down by means of the wire rope 27. The rotary movement ofbar 21 and contact member 20 is indicated by the arrows in Fig. 4a. Thegear transmission and the bar 21 are all carried by a support structure28 and the gear transmission can be driven by means similar to thoseillustrated in connection with the embodiment of Figs. 3 and 3a. Bar 21is, of course, electrically connected with the line 1.

The embodiments of Figs. 3, 3a and 4, 4a have the same principaladvantage as that inherent in Figs. 1, la and 2, namely that the forceof gravity is employed in moving the movable contact toward the fixedcontact and maintaining pressure between the two after engagementtherebetween.

The disconnect switch in accordance with the present invention is notlimited to the specific embodiments illustrated but rather itsprinciples are applicable to still further embodiments. For example, themovable, lowerable contact may be fastened to a scissor type of levermechanism mounted on the line cable, the scissor being capable ofvarious forms. However, in all embodiments the current carrying parts ofthe disconnect switch are preferably made of light-weight electricallyconductive metallic material such as aluminum or aluminum alloy.

Many advantages flow from the invention which cannot be obtained withother types of disconnect switches wherein the movable contact iscarried by the insulator pedestal and must move upward to engage thefixed contact member that is secured to the overhead line. Because thedrive is separated from the switch mechanism the supporting insulator isgreatly relieved and consequently its dimensions may be made smaller andthe cost reduced correspondingly. Also the contact engagement is muchimproved because the natural weight of the movable contact actsdownward, under the force of gravity, to thereby increase the pressureupon the fixed con tact on which it rests. By the manner of suspendingand operating the disconnect switch, a reliable closing of the switchcontacts is achieved regardless of changes in position of the overheadline due to wind presure, ice, etc. At the same time, ice formation atthe contacts and in part also at the disconnect switch itself isprevented in the embodiments of Figs. 3 and 4, namely as a result of thesmall movements of the movable contact relative to the counter, fixedcontact caused by vibrations in the line, or variations in its position.Lastly, all intermediate structures for equalizing the line vibrationsor variations in its position become unnecessary.

We claim:

1. In a disconnect switch of the vertical column type for a high voltageline where the switch contacts are structurally separated from eachother, the combination comprising an insulating support disposed belowsaid line, a fixed contact carried by said support, a movable contactelectrically connected to said high voltage line, and electricallyconductive means for lowering said movable contact from said line intoengagement with said fixed contact.

2. A disconnect switch as defined in claim 1 wherein said movablecontact is constituted by a weighted member, and said means for loweringsaid movable contact into engagement with said fixed contact iscomprised of a flexible electrically conductive cable, said weightedmember being secured to one end of said cable, and a drum upon whichsaid cable is Wound and unwound thereby to raise and lower respectivelysaid weighted member.

3. A disconnect switch as defined in claim 1 wherein said movablecontact is constituted by a weighted member, and said means for loweringsaid movable contact into engagement with said fixed contact iscomprised of a drum, a flexible electrically conductive cable adapted tobe wound on and unwound from said drum, a support for said drum, one endof said cable being secured to said support and the other end beingsecured to said drum, and said weighted member including an eye elementthrough which said cable is passed.

4. In a disconnect switch of the vertical column type for a high-voltageline where the switch contacts are structurally separated from eachother, the combination comprising an insulating support disposed belowsaid high-voltage line, a fixed contact carried by said support, amovable contact electrically connected to said highvoltage line, andelectrically conductive means for low- 7 ering said movable contact fromsaid high-voltage line into engagement with said fixed contact, saidmeans for lowering said movable contact into engagement with said fixedcontact being comprised of a toggle mechanism, said toggle mechanismincluding a first lever having one end thereof arranged for rotationabout a fixed pivot axis adjacent said line, a second lever pivotallyconnected at one end to the opposite end of said first lever, saidmovable contact being mounted on the other end of said second lever,sprockets arranged respectively at the opposite ends of said first leverconcentric with the pivot axes at such ends, a chain interconnectingsaid sprockets, said chain and sprockets being arranged to effectpivotal movement of said second lever relative to said first lever uponpivotal movement of said first lever, and means including a third leverarticulated to said first lever for effecting pivotal movement of saidfirst lever.

5. In a disconnect switch of the vertical column type for a high-voltageline where the switch contacts are structurally separated from eachother, the combination comprising an insulating support disposed belowsaid highvoltage line, a fixed contact carried by said support, amovable-contact electrically connected to said high-voltage line, andelectrically conductive means for lowering said movable contact fromsaid high-voltage line into engagement with said fixed contact, saidmeans for low ering said movable contact from said line into engagementwith said fixed contact comprising a bar having said movable contactsecured to one end thereof, said bar being mounted for rotation about anaxis intermediate the bar ends from a horizontal position adjacent andsubstantially parallel with said line to a vertical position normal tosaid line and in vertical alignment with said fixed contact, and saidbar then being lowerable longitudinally of itself thereby to bring saidcontact member into engagement with said fixed contact.

6. A disconnect switch as defined in claim 5 wherein said movablecontact member has a spade-like configuration and said fixed contact hasa trough-like configuration whereby to facilitate guiding of saidmovable contact into engagement with said fixed contact.

7. In a disconnect switch of the vertical column type for a high-voltageline where the switch contacts are structurally separated from eachother, the combination comprising an insulating support disposed belowsaid high-voltage line, a fixed contact carried by said support, agantry to which one end of said high-voltage line is secured andterminated, a movable contact electrically connected to saidhigh-voltage line and electrically conductive means including drivemeans therefor mounted on said gantry for lowering said movable contactfrom said high-voltage line into engagement with said fixed contact.

8. The invention as defined in claim 7 wherein said drive means for saidcontact lowering means is comprised of an endless drive.

9. The invention as defined in claim 7 wherein said drive means for saidcontact lowering means is comprised of an endless drive and aninsulating shaft.

10. The invention as defined in claim 7 wherein said drive means forsaid contact lowering means is comprised of a compressed air motor andwhich further includes a supplementary compressed air tank disposedparallel to the air supply line for said drive to permit manualoperation of said disconnect switch.

11. A disconnect switch as defined in claim 1 wherein said means forlowering said movable contact into engagement with said fixed contactincludes drive means therefor mounted upon a support below said line,and an endless drive transmission extending from said drive means tosaid contact lowering means.

12. A disconnect switch as defined in claim 1 wherein said means forlowering said movable contact into engagement with said fixed contactincludes drive means therefor supported on the ground below said line.

13. A disconnect switch as defined in claim 1 wherein the electricallyconductive components of said switch excepting said movable and fixedcontacts are made of light-weight metal.

References Cited in the file of this patent FOREIGN PATENTS 14,908 GreatBritain July 4, 1903 113,617 Sweden Mar. 27, 1945 168,743 Austria July25, 1951

